TweetShare on TumblrMemorial Day weekend is an ideal time to disrupt the US aviation system, when an estimated minimum of 2.6 million people are flying. Passengers on multiple flights had to go through delays when their aircraft had to be checked by officials, usually after a threat.

Air France flight 22 was the first flight threatened. As a result, two F-15s were sent to escort the Airbus A330 to New York. The military planes flew in a way so that passengers on the flight would not be able to see them.

A call to the barrack in McHenry of the Maryland State Police was received at 6:30am. The line was untraceable, but the unidentified caller said that there was a "chemical weapons threat" on Flight 22. The caller also said that four flights were threatened, but did not specify any flights other than Flight 22.

The A330 landed at 10:25am. Upon arrival, it was taken to an isolated area so the plane could be searched. Two other flights — a Saudia flight and American Airlines flight 131 — had also received threats. The Saudia flight was searched, but the American flight, which was en route from Birmingham, UK, later received notice that the threat was not credible and that taxiing to the terminal would be safe.

Over at Newark, a Delta Air Lines flight and a United Airlines flight were threatened.

All threats were possibly made by the same man, though it has not yet been confirmed and law enforcement said they were not credible. However, they believe there may be a plot to disrupt air travel in the New York City area.

In Buffalo, one crew felt there was a possibility of a threat on board their plane. A Southwest Airlines aircraft, arriving from Baltimore at 1:15pm, had dogs come aboard to sniff after passengers had deplaned. The reason for the crew's request is unknown, but it delayed the flight back to Baltimore by an hour.

Authorities say that they are responding out of an abundance of caution. If the anonymous caller had a credible threat on one plane but was attempting to distract the authorities by calling out other threats, police and other agencies wouldn't want to keep their guard down.